In the assembly of various types of equipments, such as telephone switching frames, there are continued needs for automatic tools to assemble various fasteners, such as bolts, threaded studs, washers and nuts. Switching frames are made up of angular metal sections to form housings or mountings for numerous sub-assemblies or modules of electrical, electronic and semi-conductor devices. The sub-assemblies and modules are secured in the frame by fixing threaded studs within the frame to pass through holes formed in the sub-assemblies and modules so that washers and nuts may be assembled on the projecting portion of the threaded studs.
These fastener assembly operations are time consuming and tedious when use is made of manually operated tools, such as socket wrenches. Even if power driven socket wrenches are utilized, the operator must pick up and place washers and nuts on the threaded studs prior to the final assembly with the power driven hand operated tool.
It may be appreciated that there are needs for portable apparatus that can automatically feed nuts and washers from supply sources in oriented relation so that an automatic assembly tool can function to automatically assemble the nuts and washers onto a threaded stud. Such portable apparatus should be adapted for movement with the operator for use at different work locations or for nut and washer assembly operations at diverse sites on a frame.
Bench mounted non-portable apparatuses have been designed to provide facilities for feeding washers and nuts to an assembly position whereat a socket-like automatic tool is utilized to assemble the nuts and washers on threaded bolts or studs. In U.S. Pat. No. 3,406,414 issued Oct. 22, 1968, to S. Kulaga et al., there is shown a vibratory system for feeding nuts and washers into a bench mounted facility wherein a socket is advanced to pivot gripping members out of position, whereafter the socket is advanced over the nut to move the nut along a guide pin or probe onto a threaded stud. The descending socket is rotated to thread the nut onto the threaded stud.
Other types of bench mounted devices are known to automatically assemble groups of washers on diversely located studs. One such device is shown in U.S. Pat. No. 2,910,768 issued Nov. 3, 1959, to H. W. Heidergott et al., wherein stacks of washers are positioned in lateral alignment with a number of studs so that operation of a number of pushers results in the advance of one or more washers from each stack into positions that are axially aligned with the studs. Next, a group of pilot pins are passed through the washers so that release of the washers results in the washers being guided onto the studs.